The present invention relates to electrical connectors, and more specifically concerns connectors for engaging multiconductor flat cables and connector elements and methods for making them.
Computers and many other kinds of electronics equipment rely heavily upon multiconductor cables for routing signals and power among various subassemblies and other units. Many of these take the form of flat cables having side-by-side conductors. Frequently, these cables also have flat conductors, and their covering is one or more thin layers of insulating material. In a number of applications, cables are merely extensions from flexible printed circuits. That is, the term "cable" must be taken in a broad sense as a sheathed group of mutually insulated electrical conductors. Because current and voltage levels are very low in many applications, flat cables frequently employ very small conductors and very thin insulators in order to achieve small size.
Small cables, however, require small connectors. Small connectors in turn require very small and very closely spaced contact elements for the individual conductors of the cable. One conventional configuration employs contacts spaced on 0.1 inch centers. The cable itself is capable of much closer spacing; 0.050-inch conductor spacing and even less is achievable. Connectors having two rows of contacts can render the connector not much wider than the cable. However, such connectors are relatively complex and expensive to manufacture. Often the pins that they connect to must use extra area on a circuit board for contact pins and wiring patterns, because modern printed circuit boards can easily place conductors 0.050 inches apart.
Merely reducing the size of conventional connector or contact elements is not straightforward. Smaller elements become difficult to manufacture and to handle. Their relatively complex designs require precision that leads to increased cost and wastage. Some elements have multiple pieces and must be assembled. Placing conventional elements into connector shells either by machine or by hand becomes increasingly difficult. Reliability, which is always a major problem in multiconductor connectors, suffers greatly.
Electronics manufacturers continue to request smaller and smaller multiconductor connectors for their equipment. At the present time, there is an unsatisfied demand for inexpensive, reliable flat cable connectors having contact spacings of 0.050 inch or less.